Applicability of resonant angular-momentum removal mechanisms to the multiple-impact Moon-formation scenario

Determine whether the previously proposed resonant mechanisms for angular-momentum removal in the Earth–Moon system—specifically the evection resonance with the Sun and the Laplace plane transition—apply effectively to a multiple-impact Moon-formation scenario involving sequential moonlets, and characterize the conditions under which these mechanisms operate in this context.

Background

The paper explores a multiple-impact pathway for Moon formation, where several moderate impacts build both Earth and a growing moon. In single-impact models, excess angular momentum can be reduced through resonant interactions (evection resonance and Laplace plane transition), which have been demonstrated in prior work to remove substantial angular momentum.

However, the simulations here reset angular momentum between impacts for practicality, and the authors note that while resonant mechanisms can reduce angular momentum in single-impact scenarios, it is unclear whether these mechanisms are applicable to a system experiencing multiple sequential impacts and moonlet formation.